1. Field of the Invention
The present invention relates to a base station transceiver subsystem of a mobile communication system and more particularly, to a cooling device of a linear power amplifier in a mobile communication system capable of preventing the malfunctions of the linear power amplifier caused due to overheating of a radio frequency transistor as a principal part of the linear power amplifier used in a base station transceiver subsystem.
2. Description of the Related Art
In a general mobile communication system such as, for example, a digital cellular system (DCS), a personal communication system (PCS), an IMT-2000 system and the like, a mobile station (MS) inputs and outputs the signal on the end thereof, a base station transceiver subsystem (BTS) carries out a radio communication with the mobile station, and a base station controller (BSC) controls the base station transceiver subsystem. A mobile switching center (MSC) carries out a switching for the signal transmitted from the mobile station to another communication network and a switching for the signal transmitted from another communication network to thereby connect to the mobile station.
Under the above mobile communication system, a linear power amplifier, which is secured in isolation on the one side of the interior of the base station transceiver subsystem, is a very important element serving to amplify the radio frequency signal transmitted or received.
In case of transmitting a signal from the base station transceiver subsystem to the outside, if the output of the signal is to be high, there is a need for a power amplifier having a high output. Hence, a radio frequency transistor linearly amplifying the output signal in proportion to the input signal exhibits a high heating value. In this way, the thus-generated heat should be emitted to the outside, but such the emission of the heat has been emerged as one of important factors from the viewpoint of the performance and safety of the mobile communication system.
In order to emit the heat generated in the interior of the base station transceiver subsystem, there is a conventionally proposed air-cooling type cooling device using a cooling fan. However, the conventional air-cooling type cooling device exhibits limitations in controlling a high heating temperature of the radio frequency transistor having a high output and hence, there still occurs a problem that the distortion of a circuit is caused due to the high heating temperature. Additionally, the air-cooling type cooling device should be provided with a passage communicating to the outside in order to let flesh air therein, which results in the generation of a waterproof problem and the weakness to powdered dusts.
Further, the vibration caused during the driving of the cooling fan is transmitted to peripheral devices, which results in the shortening of the life of product. Due to the noises generated by the vibration, the surrounding environment is affected, which results in the reduction of the reliability of a user for the product.
It is, therefore, an object of the present invention to provide a cooling device of a linear power amplifier in a mobile communication system capable of enabling the heat transmitted to the whole liner power amplifier from a radio frequency transistor to be cooled by using a liquid having a substantially higher coefficient of heat transfer than that of air, thereby preventing a temperature of the linear power amplifier from being risen.
To attain this and other objects of the present invention, there is provided a cooling device of a linear power amplifier in a mobile communication system, which comprises: a cooling water generating portion for generating a cooling water having a low temperature within an outer body of a base station transceiver subsystem; and a cooling portion to which the cooling water having the low temperature generated in the cooling water generation portion flow to thereby absorb a surrounding heat and then discharge the resulting water to the cooling water generating portion.